Web site hosting - Domain Names
Domain space: This is your main internet domain, where all your web files are stored. In addition, you can access your database files from here - but of course they are stored where they cannot be accessed by a browser, to keep them safe.
Sub Domain: If you have a domain called www.domain.com you can set up a sub domain called for example help.domain.com. A sub domain can be set up as a full domain with web space or as a domain pointer and is priced accordingly.
Domain Pointer: A domain pointer is a domain name that points to another domain name. For example you may wish to register both the .com and .co.uk versions of your domain name. The .com version can be linked to your web pages, and the .co.uk version points at your .com version, therefore whether someone enters the .co.uk or .com domain name into their web browser they will see the same website.
Domain pointers have no allocated web space, nor do they have mail aliases. In addition, there are no hosting fees associated with a domain pointer.
Domain pointers can be 'upgraded' to full domains.